OBJECTIVE Computed tomography (CT) imaging of children is increasing in emergent settings without an understanding of parental knowledge of potential cancer risks. In children with head injuries, our primary objective was to determine the proportion of parents who were aware of the potential of CT to increase a child's lifetime risk of malignancy. We also examined willingness to proceed with recommended CT after risk disclosure and preference to be informed of potential risks. METHODS This was a prospective cross-sectional survey of parents whose children presented to a tertiary care pediatric emergency department with a head injury. Survey questions were derived and validated by using expert opinion, available literature, and pre- and pilot testing of questions with the target audience. RESULTS Of the 742 enrolled parents, 454 (61.2%) were female and 594 (80.0%) were aged 31 to 50 years. Importantly, 357 (46.8%) were aware of the potential for an increased lifetime malignancy risk from CT. Before risk estimate provision, the proportion of parents "very willing/willing" to proceed with head CT was 90.4%; after disclosure, willingness decreased to 69.6% (P < .0001), and 42 (5.6%) would refuse the CT. Of note, 673 (90.3%) wished to be informed of potential malignancy risks. CONCLUSIONS Approximately half of the participating parents were aware of the potential increased lifetime malignancy risk associated with head CT imaging. Willingness to proceed with CT testing was reduced after risk disclosure but was a significant barrier for a small minority of parents. Most parents wanted to be informed of potential malignancy risks before proceeding with imaging.